Portable intensive care unit

ABSTRACT

A self contained manually portable intensive care unit for adults has a housing with a first minor compartment holding medical equipment at one end and a second minor compartment holding medical equipment at an opposite end, medical equipment is located between the minor compartments in predetermined positions to provide a generally balanced assembly. Oxygen storage bottles are retained on one side of a longitudinal medial region while other equipment are retained on the other side of the longitudinal medial region.

This application is a continuation of application Ser. No. 08/776,855,filed Feb. 3, 1997, now U.S. Pat. No. 5,918,331, which is a 371 ofPCT/AU95/00477, May 7. 1996.

FIELD OF THE INVENTION

THIS INVENTION relates to a portable intensive care unit and inparticular but not limited to a stretcher style mobile intensive careunit for field use.

BACKGROUND ART

The present invention has particular application on premises or sites ofoperations to provide easy access to a fully equipped life supportfacility that can be quickly transported by road or air to furtherservices that can provide the ongoing long-term treatment required sothat the present invention can be easily returned to the site andpartake in further rescue activities. This in turn enables the patientto not only receive emergency medical treatment at the point of accident(where a lack of treatment or suitable equipment may complicate theircondition), but will most definitely enhance their recovery for havingbeen treated so quickly and effectively.

Prior art solutions are generally unsatisfactory. One solution involvesa so called stretcher bridge which holds instruments and straddles astretcher, thereby bridging over the patient. While this unit hasrelatively low cost, equipment is exposed to the elements, patientaccess is restricted, the unit is relatively fragile and because of itssmall size, is not a fully self-contained unit. The unit lacks oxygensupply or power supply back-up. In addition, the unit does not satisfyair worthiness requirements.

Another unit of Israeli origin provides a single enclosure mounted tothe rear wall of an aircraft to provide a flight surgeon with a fullrange of intensive care equipment. However, unfortunately, this systemis not portable.

It is an object of the present invention to provide an alternativesystem which alleviates the aforementioned disadvantages of the priorart.

OUTLINE OF THE INVENTION

In one aspect therefore, the present invention resides in a mobileintensive care unit comprising an elongate, hollow housing having anupper patient support table, the housing being adapted to hold at alocation below the support table, a range of medical equipmentcustomarily required for emergency care. Typically the equipment isarranged in side-by-side position and the unit has handles so that theunit can be carried like a stretcher.

The housing is preferably made from a fiber reinforced resin andpreferably carbon fibre is employed as this provides strength, but alsoreduces radiant interference from electrical equipment housed in theunit. The use of carbon fibre also enables the housing to be thin walledwhilst retaining impact resistance.

The housing is preferably internally braced. Advantageously, the housingincludes an outer side wall bridging between the support table and abottom wall, the housing has at least two transverse bracing walls, oneadjacent each end of the housing, the bracing walls being interconnectedby a third longitudinally extending bracing wall generally centrallydisposed in the housing. The walls typically have an average wallthickness of 1 to 3 mm, but where necessary, the walls are locallystrengthened particularly in areas prone to concentrated load, forexample, handles or tie down sites etc. The carbon fibers are preferablylaid in layers at plus or minus forty-five degrees to improve loadingcharacteristics.

The medical equipment is typically located side-by-side on one side ofthe central wall so that medical personnel need only operate from oneside of the unit. The other side of the central wall is typically usedfor storage. Oxygen bottles are typically located at opposite ends ofthe unit and away from the medical equipment.

The support table can be flat, but can be channel-like or recessed.Typically, the support table is designed to mount a stretcher, thesupport table having four stretcher feet sockets and transverse slotsextended between adjacent sockets for receiving transverse stretcherbraces.

The housing is typically divided into a plurality of isolated medicalequipment holders including a defibrillator holder having a drawer sothat a defibrillator can be easily removed from the unit for emergencyuse.

The housing is preferably generally symmetrical in side view so that itis balanced. The unit typically includes a central cavity of generallyrectangular shape and has tapered ends extending on opposite ends of thegenerally rectangular cavity. The central cavity typically has a slidingdoor.

The housing is preferably designed so that it can be carried in anaircraft with at least four locally strengthened and evenly spacedsecuring points and most preferably eight securing points are used sothat the unit can be either tied down or hung in stackable fashion withother similar units.

The housing preferably includes lock down means provided in an undersideof the housing so that the unit can be secured to a surface such as thefloor of an ambulance. The lock down means typically comprises a pair ofskids or rails extending along the underside of the housing. The skidsor rails typically provide added structural strength to the unit and arepreferably equipped with spaced apertures so that a strap or other meanscan pass through the apertures to lock the unit in place.

The housing is preferably equipped with brackets, holders or independentlocating sites for the medical equipment so that the medical equipmentis rigidly stowed yet removably secured in the housing.

The housing preferably includes a door or doors providing protection forthe medical equipment from the elements or other contamination. One dooris typically a vertically moveable curtain. The curtain is typicallyopen in its lowered position. The medical equipment holders arepreferably arranged so that the medical equipment is set back from thedoor to further limit contamination when the door is open.

Each item of medical equipment is preferably standard, off the shelfequipment and, of course, each item of medical equipment normally hasits own power requirements. In this sense, each piece of equipment isisolated within the unit. Most preferably however, the unit employs apower supply conditioner through which power is supplied, firstly to theunit and then to each item of medical equipment. The power supplyconditioner preferably has a supply inlet for connection to mains or anyother external power source, an input circuit receiving current from theexternal source, a power supply conditioner circuit and a DC outputcircuit providing a conditioned DC output to the medical equipment. In amost preferred form, the supply inlet is adapted to receive any one ofnormally available AC or DC supplies, the conditioned supply at theoutput being isolated from fluctuations at the input to provide astandard DC voltage to the medical equipment. Typically, thedefibrillator is not connected to the power supply, but is solelysupplied by its own battery and is therefore isolated from the powersupply conditioner. Preferably, the power supply conditioner is locatedadjacent a vent in the housing to cater for variations in pressurewithin an aircraft cabin.

The unit preferably includes an oxygen supply circuit as well as thevarious power supply circuits and an electrical circuit leading from thepower supply conditioner to the medical equipment, the oxygen supplycircuit and the electrical circuit are preferably arranged so thatoxygen supply lines and electrical cables are carried on either side ofa dividing wall for safety purposes. The oxygen supply circuitpreferably includes at least two oxygen bottles and a pneumatic circuitwith oxygen supply selection means enabling selection of either of thetwo bottles or an external supply.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention can be more readily understood and be putinto practical effect, reference will now be made to the accompanyingdrawings which illustrate a preferred embodiment of the presentinvention and wherein:

FIG. 1 is a perspective view of a portable intensive care unit accordingto the present invention with the medical equipment removed;

FIG. 2 is a side view of a stretcher style mobile intensive care unitaccording to the present invention;

FIG. 3 is a plan view of the unit of FIG. 1;

FIG. 4 is side view similar to that of FIG. 1;

FIG. 5 is a section through A—A of FIG. 2;

FIG. 6 is an end view;

FIG. 7 is a general layout schematic illustrating main structuralfeatures of the unit;

FIG. 8 is a general layout schematic showing the relative positions of atypical oxygen circuit and a typical electrical circuit;

FIG. 9 is a block diagram of a power conditioner suitable for thepresent invention;

FIGS. 10A and 10B make up a circuit diagram illustrating a typicalcircuit for implementation of the power conditioner aspect of thepresent invention; and

FIG. 11 is a general layout diagram of a preferred oxygen supplycircuit.

METHOD OF PERFORMANCE

Referring to the drawings and initially to FIGS. 1 to 6, there isillustrated a stretcher style mobile intensive care unit 10 comprisingan elongate hollow housing 11 having an upper patient support table 12,the housing being adapted to hold at a location below the support table12, a range of medical equipment. The range is shown generally at 13 andbeing customarily equipment required for emergency care. The unit has,in this case, four handles 14 so that the unit can be carried like astretcher.

The unit carries its own 880 liter capacity oxygen supply in 2 “C” sizecylinders connected to a common manifold via a change over switch. Aconnection to an external oxygen supply is also available. Alarms areused to indicate a failing supply. The oxygen can be used forventilation via a ventilation unit or for variable rates of supply via astandard oxygen mask. A patient over or under pressure electronic alarmsystem, which is operator adjusted is also fitted, thus providingcontinuous monitoring of the patients breathing circuit.

Power for all the electromedical equipment is provided by an internalpower unit including a rechargeable 12 volt battery bus supported by aconditioner to regulate supply to the battery and/or the electromedicalequipment so that the bus may be connected via the conditioner to almostany available source of external power. Typical external power sourcesthat are usually available and are compatible include a road vehicle 12VD.C. supply, an aircraft 28V D.C. supply any alternating current sourcebetween 80 to 250 vac at any frequency from 50 to 400 Hz.

The unit typically holds for use six pieces of medical equipment.

A multifunction monitor is fitted capable of providingelectrocardiogram, heart rate, non-invasive blood pressure, invasiveblood pressure, pulse oximetry, and temperature measurement all throughappropriate transducers.

A ventilator is fitted with infinitely adjustable respiratory frequency(approx. 10 to 30 breaths per minute) and minute volume (approx. 2 to 20liters per minute) settings.

The capability of selecting either 100% oxygen or an oxygen/air mixturewithout changing minute volume is also available.

A demand valve and mask is also fitted together with pre-settable oxygentherapy and face mask.

A breathing circuit disconnect alarm unit is included such that theoperator may select both high and low pressure alarm indications.

An electric volumetric infusion pump is fitted having adjustableinfusion rates up to 999 ml/hr increments.

A syringe pump is fitted for continuous micro infusion. The unit accepts50 ml syringes and has adjustable flow rates up to 150 ml/hr in 0.1ml/hr increments.

An electric compact suction unit is fitted having adjustable vacuumlevels from 200 to 500 mmHg.

A Defibrillator is fitted which can also act as an ECG monitor. The unitmonitors ECG and chest impedance prior to arming itself for shockdelivery.

A portable anaesthetic machine can be temporarily attached to the unitfor field surgical procedures.

Consideration in designing the unit has been given to its use not onlyin tactical and strategic AME situations in both fixed and rotary wingaircraft, but also in field ambulances, field and general hospitals,mobile field surgical teams and the parachute surgical team.

In one application of the invention, as illustrated in FIG. 2, astandard NATO styled stretcher 15 (in phantom in FIGS. 3, 4 and 5) isshown located on and above the patient support table 12, the stretcherbeing located in place by sockets 16 into which the feet 17 of thestretcher 12 automatically locate. In the case of the NATO styledstretcher, an arcuate brace extends down from the stretcher at about thelevel of the feet 17 and extends transversely across the stretcher. Thepatient support table 12 includes transverse recesses 18 to take intoaccount this brace. The patient support table 12 is generally recessedand includes adjustable eyelets 19 on sides thereof which can be movedlongitudinally along the unit for the purpose of providing sites forstraps to secure a patient and therefore the stretcher in place.

It will be appreciated however, that the support table can be configuredto carry any suitable stretcher or any other patient support.

In the illustrated embodiment, the items of medical equipment include adefibrillator held at first minor compartment 20 on a sliding carriageor drawer 21, the defibrillator being isolated from the other medicalequipment, a suction unit at 22, a ventilator and oxygen module at 23, amulti-function monitor at 24, a volume infusion pump at 25 forparenteral fluids and a syringe infusion pump at 26 second minorcompartment. All of the medical equipment is accessible from one side ofthe unit and the opposite side of the unit includes doors for access tothe interior for storage purposes. A sliding curtain 27 is used to coverthe medical equipment housed in the generally rectangular cavity 28. Thefront faces of the medical equipment are generally recessed back fromthe curtain 27 to limit contamination. The defibrillator and the syringeinfusion pump are located behind hinged doors. The whole unit cantherefore be closed for transportation purposes.

The unit is balanced by virtue of the arrangement of compartments andcomponents within the unit and the generally symmetrical stretcher stylearrangement of the unit. The unit can be comfortably handled by fourpeople when loaded with a patient and can be carried in the fashion of asuitcase when unloaded.

In FIGS. 2, 4, and 5 the unit includes a pair of spaced rails 33 havingapertures 34 so that the unit can slide into an ambulance and be lockedin place adjacent the standard rails inside the ambulance. A lockingmeans such as a strap or the like is generally used and is insertedthrough the apertures 34 for this purpose.

The general structural layout is shown in FIG. 7 in a schematic formwhere two walls 29 and 30 extend transversely across the unit adjacentopposite ends of the unit. A longitudinally extending wall 31 bridgesbetween the walls 29 and 30 thereby providing structural integrity forthe unit. The unit is made from carbon fibre reinforced resin, it has anaverage wall thickness of around 2 to 3 mm with the wall beingstructurally thickened and stronger at the handles 14 and at tie downsites 32 (see FIGS. 1, 2 and 3), it being appreciated that the unit caneither be tied down or can be hung via the handles 14 and theirmountings to the unit. It is most typically hung and stacked in hungpositions at various heights when being transported by aircraft. In theillustrated embodiment therefore, there are eight securing sites forsecuring the unit in the aircraft or in other transportation means.

Referring now to FIG. 8, there is illustrated in schematic form theoxygen and electrical layout of the unit and, in this case, a pair ofoxygen bottles 35 and 36 are employed with high pressure lines 37 and 38leading to the ventilator and oxygen control module shown generally at23, the unit is provided with a power conditioner at 39 and this has acable at 40 communicating with each item of electric equipment locatedin the rectangular cavity shown generally at 28. Associated with eachitem of equipment is a wall or bracket or a separate container which isshown schematically by the dotted lines at 41, 42 and 43, these enablethe items of medical equipment to be rigidly secured in the cavity 28,but still be removable and interchangeable, for example, the units mayneed to be removed and interchanged for cleaning purposes. Theelectrical cable 40 has separate independent connectors for each item ofequipment.

Referring now to FIG. 9, there is illustrated a typical conditionercircuit 44 employing an AC power input at 45 and a DC power input at 46.The AC input is arranged to generally accept voltages from 80 to 240volts AC and at a frequency from 47 H_(z) to 400H_(z), while the DCinput accepts voltages in the range of 8 to 32 volts DC. A proprietaryAC to DC inverter 47 and a proprietary DC to DC converter 50 suppliespower to the proprietary battery charger 48 to charge an auxiliarybattery 49.

The unit is equipped with a power selector switch shown generally at 50,which enables a user to either select AC input or DC input or power fromthe auxiliary back-up battery 49, the outcome being the delivery of asteady 13.8 volts DC to the medical units supplied at 51. Each of themedical units is shown generally at 52 connected to the bus 51. Asmentioned previously, each of the medical units has its own batterysupply and charging capability, so when AC or DC input power isconnected to 45 or 46, the auxiliary battery is charged and each of thebatteries of the corresponding medical equipment are also charged. Inthe present case, a 9 volt DC supply is required for the nominallyselected ventilator alarm at 53 and a voltage regulator 54 is providedon the bus to account for this.

A more detailed circuit is illustrated in FIG. 10A, 10B and whereappropriate, like numerals have been used to illustrate like featureswith the significant additional variations being the inclusion ofvaristors at 55, 56 and 57 to inhibit susceptibility interference,filters at 58 and 59 to prevent conducted emissions and high frequencyfiltration at 59 to prevent interference with aircraft avionicsequipment. The whole circuit is located within a faraday cage to preventradiated interference and as the housing itself is also made from acarbon fibre reinforced resin, this provides additional shielding.

Referring now to FIG. 11, there is illustrated, a typical pneumaticcircuit involving the two gas bottles 35 and 36 and high pressure lines37 and 38 which communicate with a regulator at 61 and in turn with asource selector valve 62. The source selector valve 62 enables selectionof an external oxygen source supplied via fitting 63 or the internalsource from bottles 35 and 36. Non return valves 64 and 65 enable thebottles 35 and 36 to independently be exchanged for a fresh supply.

Item 66 is a demand valve and item 69 is an outlet for oxygen therapypurposes. Oxygen is supplied to the ventilator unit 68 which is part ofthe oxygen module 23. This is also equipped with an oxygen disconnectalarm at 69. Supply pressure warning gauges 71 and 72 are provided forchecking the contents of the bottles 35 and 36.

Whilst the above has been given by way of illustrative example of thepresent invention, many variations and modifications thereto will beapparent to those skilled in the art without departing from the broadambit and scope of the invention as set forth in the appended claims.

What is claimed is:
 1. A manually portable intensive care unitcomprising: an elongated hollow housing having a first end, a second endopposite the first end, an upper patient support table and a lowermedical equipment enclosure extending below the support table providedinternally thereof with compartments for containing medical equipment,the housing having a first minor compartment holding medical equipmentat the first end of the housing and a second minor compartment holdingmedical equipment at the second end of the housing, the first and secondminor compartments being separated by medical equipment retained in thehousing in predetermined positions to provide a generally balancedassembly for manually bearing an adult patient in a prone position onthe support table.
 2. A manually portable intensive care unit accordingto claim 1, wherein the housing includes opposite longitudinal edges andthe unit further comprises an oxygen storage vessel located within thehousing the oxygen storage vessel extending along a side of the housingin close proximity to one of said longitudinal edges of the housing. 3.A manually portable intensive care unit according to claim 1, furthercomprising at least one oxygen storage vessel extending along one sideof the housing, and the medical equipment separating the first andsecond minor compartments being positioned within the housingsubstantially on a side of the housing opposite to said oxygen storagevessel.
 4. A manually portable intensive care unit according to claim 1,wherein the medical equipment separating the first and second minorcompartments includes a ventilator and a suction unit, the ventilatorand suction unit being disposed toward one side of the housing.
 5. Amanually portable intensive care unit according to claim 1, wherein thehousing includes a centrally disposed ground engaging base defining alower level of the unit, each of the minor compartments including a baselocated at a level above the lower level of the unit, the bases of saidminor compartments being spaced from the ground when the ground engagingbase is located on the ground.
 6. A manually portable intensive careunit according to claim 1, wherein the housing includes a longitudinallyextending medial region between the minor compartments, the medicalequipment separating the first and second minor compartments beingpositioned within the housing substantially to one side of the medialregion.
 7. A manually portable intensive care unit according to claim 1,wherein the housing includes opposite longitudinal edges and the careunit further comprises: an oxygen storage vessel located within thehousing, the oxygen storage vessel extending along a side of the housingin close proximity to one said longitudinal edge of the housing, and themedical equipment separating the first and second minor compartmentsincluding a ventilator and a suction unit, the ventilator and suctionunit being disposed toward one side of the housing.
 8. A manuallyportable intensive care unit according to claim 1, wherein the housingincludes opposite longitudinal edges, the care unit comprising an oxygenstorage vessel located within the housing, the oxygen storage vesselextending along a side of the housing in close proximity to one saidlongitudinal edge of the housing, the housing including a centrallydisposed ground engaging base defining a lower level of the unit, eachof the minor compartments including a base located at a level above thelower level of the unit, the bases of said minor compartments beingspaced from the ground when the ground engaging base is located on theground.
 9. A manually portable intensive care unit as in claim 1,wherein said housing is impact resistant and lightweight construction.